Golf club

ABSTRACT

The present invention relates generally to a golf dub. In particular, the present invention relates to a golf club in which the golf club head comprises granite or a natural or synthetic, granite-like stone, a composite, or a similar material. More particularly, the present invention relates to a golf putter.

The present invention relates generally to a golf club. In particular, the present invention relates to a golf dub in which the golf dub head comprises granite or a natural, granite-like stone, a composite, or a similar material. More particularly, the present invention relates to a golf putter.

Golf clubs are well known and include a golf dub head, shaft, and grip. The head includes a front strike face. Heads typically have an intended contact region centrally positioned on the strike face and commonly referred to as the “sweet spot.” A golf ball, upon contact with the sweet spot of the strike face, will typically and consistently travel a distance and in a direction that is directly proportional to the speed of the dub head at impact.

Conversely, when a user contacts the golf ball at a position away from the intended contact region, commonly referred to as a “mis-hit”, the ball will typically travel a distance that is significantly less than intended, or at an angle to the desired direction, that is, a “hook” or “slice”, or both, than that of a ball contacted at the intended contact region of the strike face. Moreover, the distance loss, hook, or slice can be variable and unpredictable. In an effort to increase the size of the sweet spot of a golf club, many heads are configured with various combinations of weighting to change the golf club's moment of inertia. A golf dub with an increased moment of inertia is more resistant to twisting during a mis-hit and, therefore, enables the performance of a mis-hit ball to more closely match the performance of a ball contacted at the sweet spot. However, weighting alone generally does not eliminate the distance loss or misdirection that typically occurs as a result of a mis-hit.

When a user contacts a golf ball with a golf club at the intended contact region of the strike face, the club typically generates an amount of audible and vibrational energy that provides the user with sound indicative of solid contact with the ball and a corresponding “feel”. In efforts to improve the feel of a golf dub upon impact, many heads include an insert, typically of uniform thickness, mounted into the strike face and/or within the head. Depending upon the golf dub, such inserts may be harder or softer than the material out of which the head itself is made. For example, in the case of a driver, the head is typically made of wood and the insert is typically made of a hard metal such as, for example, steel or titanium. In the case of a putter, the head is typically made of metal and the insert is typically made of a material which is softer such as, for example, plastic or polymer.

A variety of golf dub heads have been developed which are intended to reduce the number of mis-hits, improve the feel of the golf club stroke upon impact of the head with the ball, or both. For example, U.S. patent Publication No. 2003/0045372 A1 discloses a putter having an insert of variable thickness that increases the size of the putter's sweet spot. U.S. Pat. No. 6,533,680 B2 discloses a putter having an improved weight distribution which alters the head is center of gravity in order to reduce the number of mis-hits. U.S. patent Publication No. 2003/0054899 A1 discloses a golf putter in which the putter head is made of a strengthened, triangular shaped, kiln formed glass.

However, there is still a need for improved head design in order to further reduce the number of mis-hits and improve the feel when the golf club strikes the ball.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one embodiment of the present invention in which the golf dub is a putter.

FIG. 1 is a schematic, cross-sectional front view of a golf dub of this invention.

FIG. 2 is a schematic top view of a club head of this invention.

FIG. 3 is a cross-sectional side view of a club head of this invention.

The following description generally applies to a golf club of this invention wherein the golf club is a putter. However, the description can apply equally well to other types of golf clubs such as, for example, drivers.

FIG. 1 illustrates a schematic, cross-sectional, front view of a putter 10 for a right-handed golfer. The putter 10 includes a putter head 13, a shaft 14, and a grip 16. The putter head 13 is an elongate body with a toe portion 12 and a heel portion 15. The putter head 13 includes a main body 18 and an insert 20.

The shaft 14 is an elongate tube having a distal end 22, which is coupled to the dub head 13, and a proximal end 24, which is slidably connected to a grip 16. Optionally, the grip 16 may be permanently connected to the shaft 14 or may be integrated into the shaft 14. The shaft 14 is made of a generally lightweight, strong material, preferably graphite or steel Alternatively, the shaft can be formed of other materials, such as, for example, other metals or alloys, composites, or wood. In one embodiment, the shaft 14 includes an inward taper that generally extends from the proximal end 24 to the distal end 22. Alternatively, the shaft 16 can be formed having a uniform diameter along its length.

The grip 16 is a conventional handle structure of generally hollow construction. The grip 16 has an open end configured for slidably receiving the proximal end 24 of the shaft 14. The grip 16 is typically formed of a generally soft resilient material such as, for example, rubber, polyurethane, leather, a thermoplastic, or an elastomer. In an alternative embodiment, the grip 16 can be formed of two or more layers of material. In such cases, the layers may be constructed of the same or of different materials. In a further embodiment, the grip 16 can be formed by wrapping of one or more tapes about the proximal end 24 of the shaft 14. In an additional alternative embodiment, the grip 16 is formed integrally with the shaft 14 such that the grip 16 and the shaft 14 form a “one-piece” unit of uniform construction. In another further embodiment, the grip 16 is formed of wood, a composite material, or a combination thereof.

FIGS. 2 and 3 illustrate the main body 18 and the insert 20 of the putter head 13 in greater detail. The main body 18 includes a toe portion 12, a heel portion 15, a sole portion 33, a top portion 37, and a front face 35 a. Front face 35 a and the corresponding front face 35 of the insert 20 will collectively be referred to as front face 35 when referring to the head 13 as a whole. The front face 35 may be at 90 degrees to the sole portion 33. That is, when the putter is placed on a flat, horizontal surface, the front face 35 is vertical. In a preferred embodiment, the front face 35 is at an angle, referred to as the “loft angle”, 34 to the sole portion 33. The loft angle 34 is typically less than 10 degrees, preferably between zero and seven degrees, more preferably between 4 and 4.5 degrees, and most preferably 4.5 degrees, measured counterclockwise from the 90 degree angle of the front face 35 when the sole portion 33 is on a flat, horizontal surface and the club is oriented as in FIG. 3.

The main body 18 contains a recess 25, extending rearwardly from the front face 35 and defined by sidewalls 21, rear wall 23, and top wall 39, extending from the toe portion 12 to the heel portion 15 and from the top portion 37 to the sole portion 33. The recess 25 is configured to receive the insert 20. The recess 25 may optionally have a bottom wall opposite the top wall 39 in the sole portion 33. In this optional embodiment, the recess 25 is configured to enclose all but the front face 35 of the insert 20.

Referring again to FIGS. 2 and 3, the main body 18 may optionally contain a second recess 32 extending rearwardly from the rear wall 23 toward the back face 31. This second recess 32 is defined by sidewalls 320, rear wall 322, top wall 324, and bottom wall 326. The second recess 32 is configured to receive a weight 328. The weight 328 increases the moment of inertia of the putter head 13 and increases its resistance to twisting in response to mis-hit shots. The weight 328 substantially fills the second recess 32 and may be any dense material such as, for example, a metal such as, for example, steel or lead, or a dense composite material. In a preferred embodiment, the weight 328 is lead. The weight of the weight 328 may vary depending upon the total weight of the putter 10, more particularly the putter head 13. This, in turn, may vary with the weight of the insert 20 in order to give the putter 10 the weight distribution desired by the golfer. The optional weight 328 typically will weigh between 2 and 6 ounces (56 to 168 grams), preferably between 3 and 5 ounces (84 to 140 grams), most preferably 4 ounces (112 grams). In one embodiment, the second recess 32 is configured in such a manner that the weight 328 is poured into the recess 32 while in a liquid state. In such an embodiment, the weight 328 completely fills the recess 32. In an alternative embodiment, the weight 328 is held in the recess 32 by an adhesive or an adhesive agent. In a preferred embodiment, the recess 32 is sized such that it is completely filled with weight 328.

For purposes of this invention, all described ranges are inclusive and combinable. The term “cm” means centimeters.

The top portion 37 may optionally incorporate a sight line extending from the front face toward the back face, a raised or recessed dot, or other indicator of the location of the optimal strike point on the face 35. This sight line, dot, or indicator is typically made of a material with a color contrasting with that of the main body 18. The sight line may also be engraved into the top portion 37. The sight line assists the user in identifying the intended strike point of the golf dub head, particularly when the golf club is a putter wherein the sight line assists the user in properly lining up or measuring his or her putt.

Again, referring to FIGS. 2 and 3, upwardly extending from recess 380 in insert 20 through opening 26 in top portion 37 is a means 38 for connecting the club head 13 to the distal end 22 of shaft 14. Such means 38 includes, for example, a hollow or solid rod, a stud, a bolt, a screw, a hostel, or similar means. In a preferred embodiment, the means 38 is an extension configured for slidably engaging the distal end 22 of the shaft 14. In such cases, the distal end 22 may engage means 38 by extending into the inside, if the means 38 is hollow, or over the outside of the means 38. The distal end 22 of shaft 14 may be attached to the means 38 by a variety of methods known to those in the golf club art including, for example, using a adhesive or adhesive agent, welding, by friction alone, by means of a threaded joint, or an expansion connector. Optionally, the distal end 22 of shaft 14 may extend into recess 380 and be affixed directly to insert 20. The means 38 may be affixed to the insert 20 using a variety of methods such as, for example, using an adhesive or adhesive agent, careful fitting of the means 38 into the recess 380 such that the means 38 is held by friction alone, or through the use of an expansion connector or threaded joint. Optionally, the recess 380 may extend entirely through insert 20 and means 38 may be affixed to the insert 20 using an alternate attachment method such as, for example, a nut, bolt, or screw. As a further option, an additional recess may be incorporated into the club head 13 from the side or back of the club head extending to the recess 380. In such cases, the means 38 may be held in place in the recess 380 by means of a fastener such as, for example, a rod, screw, bolt, or Allen screw. In such cases, the additional recess may be threaded, to accept the bolt or Allen screw, or unthreaded, to accept a screw, rod, or similar fastener. In another alternate embodiment, the club head 13 may be connected to the distal end 22 of shaft 14 directly to the main body 18 rather than to the insert 20.

In the embodiment of this invention illustrated in FIGS. 1-3, the means 38 engages the distal end 22 of shaft 14 at an angle 11. In one embodiment, this angle is 180 degrees. In other words, the shaft 14 is straight. In such cases, the recess 380 and means 38 are configured at an appropriate angle in insert 20 to accept the straight shaft 14. In a preferred embodiment, the shaft 14 is angled. In a more preferred embodiment, the angle 11 is no greater than 20 degrees from vertical when the sole portion 33 is on a flat surface. In another preferred embodiment, the bend incorporating angle 11 is within 5 inches (12.7 cm.) of the club head 13. In a further embodiment, angle 11 is adjustable utilizing any of a variety of means for adjusting the angle. When adjustable, angle 11 is preferably adjustable from 10 to 20 degrees from vertical.

Typically, insert 20 substantially fills the recess 25 and is connected to the side walls 21, top wall 39, rear wall 23, and, when present, the optional bottom wall.

In one embodiment of this invention, insert 20 is made of a hard natural or synthetic stone material. Preferably, the stone is a natural stone material. For purposes of this invention, “hard” means that the stone material has a hardness greater than 5 on the commonly used Measurement of Hardness Scale (“MOHS”). In the MOHS talc has a hardness of 1 and diamond a hardness of 10. In one preferred embodiment, the hardness of the stone material is from 6 to 7. In a second preferred embodiment, the stone material is a natural igneous stone. In a more preferred embodiment, the igneous stone is granite. Granite primarily comprises quartz, feldspar, and other minor components. A typical granite will contain 35% by weight quartz (MOHS=7) and 45% by weight feldspar (MOHS=6) along with minor components, primarily potassium and mica. In an alternate embodiment, the granite meets the structural specifications of the National Building Granite Quarries Association, Washington, D.C., USA. Such specifications include the following based upon American Society of Testing and Materials (ASTM) tests C97, C99, C170, and C880 (all tests conducted dry on the strongest plane of the granite): Absorption by weight 0.40% Min. density 160 lbs/CuFt (2,560 kg/m3) Min. Modulus of Rupture 1,500 psi (10.34 Mpa) Min. Compressive Strength 19,000 psi (131 Mpa) Min. Flexural Strength 1,200 psi (8.27 Mpa)

The insert 20 can be a single stone or multilayered in which the layers are made up of the same stone or type of stone or different stones. In an alternate embodiment, the insert 20 can be multilayered with one or more layers made up of a synthetic or natural stone material and one or more layers made up of an alternate material. Such alternate materials include, for example, metals such as, for example, titanium, bronze, or copper; composites such as, for example, a ceramic, a polymer, or other plastic material; or wood. Preferably, the insert 20 is a single stone. For aesthetic reasons, the insert 20 is preferably granite with a pleasing color combination or mineral grain pattern.

The hard stone, particularly when it is also a dense stone such as granite, provides a “soft” feel to the golfer upon impact of the golf club with the ball. This soft feel is further improved by the make-up of the main body 18 of the head 13. The main body 18 can be made of a variety of materials such as, for example, a metal such as, for example, titanium, bronze, or copper; a composite such as, for example, a ceramic, a polymer, or other plastic material; or wood. In a preferred embodiment, the main body 18 is wood. In an alternate preferred embodiment, the wood is a hardwood. Again, for aesthetic reasons, it is preferred that the wood have a pleasing color and grain structure to complement the insert 20.

In an alternate embodiment of the head 13, the insert 20 extends forward from the main body 18 such that only the front face 35 will contact the ball when the club strikes the ball. In a further alternate embodiment, the insert 20 is constructed in such a manner that the front face 35 extends up to, or beyond the side walls 21, the top wall 39, or both. In one version of this alternate embodiment, the insert 20 itself forms the toe portion 12 and the heel portion 15 of the head 13. In this embodiment, the “recess” 25 is defined by the real wall 23 and, optionally, the top wall 39. In still a further embodiment, the insert 20 extends from the top portion 37 to the sole portion 33. In this embodiment, the “recess” 25 in the main body 18 is defined only by the rear wall 23. In this alternate embodiment, the insert 20 is enclosed only by the rear wall. In this further alternate embodiment, again, only the front face will contact the ball when the dub strikes the ball. The height and width of insert 20 may vary from bottom to top and from side to side within the recess. Thus, in the various embodiments of this invention, the recess 25 is defined by anywhere from one to five of the various walls. Furthermore, each of the walls may independently partially or fully cover the corresponding side or sides of the insert 20.

The main body edges 36, the insert edges 30, or both may be square, rounded (as depicted in FIG. 3), or have any of a number of decorative profiles depending upon the desire of the user. Preferably the edges are rounded.

In a typical example of one embodiment of a putter head 13 of this invention, the head measures 4.75 inches (12.2 cm) from the toe portion 12 to the heel portion 15, 2 inches (5.1 cm) from the front face 35 to the back face 31, and 1.0 inch (2.5 cm) from the top portion 37 to the sole portion 33. The recess 25 typically measures 3.75 inches (9.6 cm) between the side walls and 1.25 inches (3.2 cm) from the front face 35 of the insert 20 to the rear wall 23, and has a depth from the sole portion 33 to the top wall 39 of 0.875 inches (2.2 cm). The opening 26 is typically located 1.125 inches (2.9 cm) from the heel portion 15 and 0.8125 inches (2.1 cm) from front face 35. Opening 26 is typically 0.3125 inches (0.9 cm) in diameter. In actual practice, these measurements may vary considerably due to variations in the overall shape of the head 13, the materials used in construction of the insert 20 and the main body 18, the desired overall weight of the head 13, and other considerations and desires of the user. However, in practice, the length from the toe portion 12 to the heel portion 15 will not exceed 5 inches (12.7 cm) and the total volume of the head 13 will not exceed 470 cubic cm. In another example of a putter head 13 of this invention, the length from the toe portion 12 to the heel portion 15 is twice the depth from the front face 35 to the back face 31.

In an alternate embodiment of this invention, the entire head 13 comprises granite. This embodiment can be viewed as one in which the insert 20 also comprises the main body 18 as a single unit. In this embodiment, the head 13 may be constructed of a single stone may be multilayered.

In one embodiment of this invention, the overall minimum length of the golf dub 10 is at least 18 inches (45.72 cm) measured from the end of the grip 16 along the axis of the shaft 14 or a straight line extension thereof, to the sole portion 33 and the overall maximum length of the golf club 10 is 48 inches (121.92 cm) measured from the ground plane to the end of the grip 16 with the shaft 14 at a 60-degree lie angle (i.e. to the ground).

The advantage of a golf club of this invention is in its balance. By modifying the size, shape, and weight of the main body 18, the insert 20, and the optional weight 328, as well as the positioning of the means 38 and the length and angle of the shaft 14 the user can obtain a golf club which is balanced such that the face is square with the ball upon impact. In addition, the combination of the insert 20 with the main body 18 provides a golf club with improved feel when the club strikes the ball.

While the preferred embodiments of the present invention have been described and illustrated, numerous departures therefrom can be contemplated by persons skilled in the art. 

1. A golf club comprising: a) ahead; b) a shaft; and c) a grip; wherein the head comprises a hard, synthetic or natural stone.
 2. The golf club of claim 1, wherein the stone is granite.
 3. The golf dub of claim 1, wherein the head is an elongate body which comprises: a) a main body comprising a toe portion, a heel portion, a sole portion, a top portion, and a front face; and b) an insert; wherein: i) the main body contains a recess, extending rearwardly from the front face and defined by a rear wall and one or more of; one or two sidewalls, a top wall, and a bottom wall, extending from the toe portion to the heel portion and from the top portion to the sole portion and wherein the recess is configured to receive the insert; and ii) the insert substantially fills the recess and is connected to the rear wall, and, when present the one or more side walls, top wall, and bottom wall.
 4. The golf club of claim 3, wherein: a) the main body contains a second recess, extending rearwardly from the rear wall toward the back face and defined by sidewalls, a rear wall a top wall, and a bottom wall and wherein the second recess is configured to receive a weight; and b) the weight substantially fills the second recess.
 5. The golf dub of claim 3, wherein the insert comprises a hard natural or synthetic stone with a hardness, as measured by the Measurement of Hardness Scale, of from 6 to
 7. 6. The golf dub of claim 3 wherein the insert comprises granite.
 7. The golf dub of claim 3 wherein the main body comprises wood.
 8. The golf dub of claim 1 wherein the golf dub is a putter.
 9. A golf dub head comprising an elongate body which comprises: a) a main body comprising a toe portion, a heel portion, a sole portion, a top portion, and a front face; and b) an insert comprising a hard, synthetic or natural stone; wherein: i) the main body contains a recess, extending rearwardly from the front face and defined by a rear wall and one or more of; one or two sidewalls, a top wall, and a bottom wall, extending from the toe portion to the heel portion and from the top portion to the sole portion and wherein the recess is configured to receive the insert; and ii) the insert substantially fills the recess and is connected to the rear wall, and, when present the one or more side walls, top wall, and bottom wall.
 10. The golf dub of claim 1 wherein the head further comprises a multilayered structure wherein one or more layers comprise a natural or synthetic stone material and one or more layers comprise one or more alternate materials selected from metals, composites, and wood. 